Oil pressure, oil pump, pressure sensor, 1990 200...

["Gerard van Vaugh" <gerard@acenet.co.za>]

Hi!

This is me again with my oil pressure
problem in my 1990 200t. I think I've
worked this topic into the ground.
I thought I had it licked when I changed
oil and filter some 2 months ago and the
problem completely died away. Now it has
returned in full strength. After a cruise
or after a very hard run my oil pressure
will drop as low as 1 bar. Sometimes it
drops to 1 - 1.5 bar and bobs around
there somewhat violently.

I am running a Castrol semi-synth with a
o.e oil filter. Is it simply too much
gunk in the motor with the oil filter
getting clogged within 2 months or perhaps
the o.e filter cannot handle semi-synth
oil?

Last mechanic told me new oil pump needed
when he checked the oil pressure. Would
a oil pump pressure problem vanish with
an oil change?

Can this be just a faulty oil pressure
sensor? If that was the case then how
could the problem vanish with an oil
change?

I thought this was a temperature problem
as the problem raised its head on Friday
when it was fairly warm here. It was a
nice warm weekend, the motor was running
5-10 celcius hotter and I thought it was
related. However, this thing returns at
night when the motor is running about
87 celcius or cooler.

Damn! I thought I had avoided forking out
lots of cash on an oil pump! $350 or so
for a new one, $50 for a 2nd hand unit
with probably no guarantees.

Some backgroud about the problem. First
appeared after a sump gasket change at the
end of 1997, with a camshaft seal replacement
some 2 months before that. Had changed to a
Duckhams synth oil at the time which opened
lots of leaky pores. Also, turbo oil return
line was leaking and they patched it will
a clamp-like tubing. I understand that that
has no bearing on the problem.

This has really got my tiny brain stumped!

Any ideas on how to check and hunt the
source down of this problem short of pulling
the oil pump and redoing oil filters and
everything else related to the lube system?

Lifters clattered alot before the oil change.
Could this just be something like a bunch
of really oil and warn lifters? Silly question
I guess, but what do I know?

G.